Particulate matter measurement device

Abstract

Disclosed is a particulate matter measurement device that continuously measures changes in a mass of particulate matters contained in an exhaust gas under dynamic operating conditions. The device dilutes and separates the flow of exhaust gas while an engine is operating. The particulate matters contained in one of the exhaust gas streams are collected by a collection filter to measure the mass and the remainder is measured by a mass-related value measurement. Then, time series change data for the mass of the particulate matter are found based on correlations of the individual measured data. With this arrangement, the flow volume of the dilute exhaust gas that passes through the collection filter and the flow volume of the dilute exhaust gas that is introduced into the mass-related value measurement device are ensured by adjusting the flow volume of the diluting gas that dilutes the exhaust gas.

The invention claimed is: 
     
       1. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a particulate matter sensor into which a part of the diluted exhaust gas diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a valve that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a mass flow controller that adjusts a flow rate of the diluted exhaust gas passing, the collection filter, and 
 at least one controller programmed to keep a flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the mass flow controller, to secure a necessary flow rate of the diluted exhaust gas introduced into the particulate matter sensor by controlling the valve, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period, as being a time series change data of the mass-related value measured by the particulate matter sensor, and to convert the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       2. The particulate ma measurement device described in  claim 1  wherein the particulate matter measurement device is loaded on the automobile which runs on a road and measures the particulate matters in the exhaust gas while the automobile is running. 
     
     
       3. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a particulate matter sensor into which a part of the diluted exhaust gas diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a valve that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a mass flow controller that adjusts a flow rate of the diluted exhaust gas passing the collection filter, and 
 at least one controller programmed to keep as sum of the flow rate of the diluted exhaust was introduced into the particulate matter sensor and the flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the mass flow controller based on the flow rate of the diluted exhaust gas introduced into the particulate matter sensor, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the particulate matter sensor, and to convert the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       4. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a sensor into which a part of the diluted exhaust gas diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a dilution gas flow rate controller that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a filter passing flow rate controller that adjusts a flow rate of the diluted exhaust gas passing the collection filter, and 
 at least one controller programmed to keep a flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the filter passing flow rate controller, to secure a necessary flow rate of the diluted exhaust gas introduced into the sensor by controlling the dilution gas flow rate controller, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the sensor, and to convert, the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       5. The particulate matter measurement device described in  claim 4  wherein the particulate matter measurement device is loaded on the automobile which runs on a road and measures the particulate matters in the exhaust gas while the automobile is running. 
     
     
       6. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a sensor into which a part of the diluted exhaust as diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a dilution gas flow rate controller that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a filter passing flow rate controller that adjusts as flow rate of the diluted exhaust gas passing the collection filter, and 
 at least one controller programmed to keep a sum of the flow rate of the diluted exhaust gas introduced into the sensor and the flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the filter passing flow rate controller based on the flow rate of the diluted exhaust as introduced into the sensor, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the sensor, and to convert the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       7. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from n engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a sensor into which a part of the diluted exhaust gas diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a valve that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a filter passing flow rate controller that adjusts a flow rate of the diluted exhaust gas passing the collection filter, and 
 at least one controller programmed to keep a flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the filter passing flow rate controller, to secure a necessary flow rate of the diluted exhaust gas introduced into the sensor by controlling the valve, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the sensor, and to convert the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       8. The particulate matter measurement device described in  claim 7  wherein the particulate matter measurement device is loaded on the automobile which runs on a road and measures the particulate matters in the exhaust gas while the automobile is running. 
     
     
       9. A particulate matter measurement device comprising:
 a mixer that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a sensor into which a part of the diluted exhaust gas diluted by the mixer is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a valve that adjusts a flow rate of the dilution gas introduced into the mixer, 
 a filter passing flow rate controller that adjusts a flow rate of the diluted exhaust gas passing the collection filter, and 
 at least one controller programmed to keep a sum of the flow rate of the diluted exhaust gas introduced into the sensor and the flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the filter passing flow rate controller based on the flow rate of the diluted exhaust gas introduced into the sensor, to calculate a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the sensor, and to convert the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       10. A particulate matter measurement device comprising
 a dilutor that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a mass-related value measurement device into which a part of the diluted exhaust gas diluted by the dilutor is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a dilution gas flow rate adjusting device that adjusts a flow rate of the dilution gas introduced into the dilutor, 
 a filter passing flow rate adjusting device that adjusts a flow rate of the diluted exhaust gas passing the collection filter, 
 a control part that keeps a flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling, the filter passing flow rate adjusting device and that secures a necessary flow rate of the diluted exhaust gas introduced into the mass-related value measurement device by controlling the dilution gas flow rate adjusting device, and 
 an information processing part that calculates a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the mass-related value measurement device and that converts the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation. 
 
     
     
       11. The particulate matter measurement device described in  claim 1  wherein the particulate matter measurement device is loaded on the automobile which runs on a road and measures the particulate matters in the exhaust gas while the automobile is running. 
     
     
       12. A particulate matter measurement device comprising
 a dilutor that is connected to an exhaust pipe of an automobile and connected to a dilution gas introducing inlet and that mixes an exhaust gas from an engine of the automobile with a dilution gas so as to dilute the exhaust gas, 
 a mass-related value measurement device into which a part of the diluted, exhaust gas diluted by the dilutor is introduced and that continuously measures a mass-related value indirectly indicating a mass of particulate matters contained in the diluted exhaust gas, 
 a collection filter through which the remainder of the diluted exhaust gas passes and that collects the particulate matters contained in the remainder of the diluted exhaust gas, 
 a dilution gas flow rate adjusting device that adjusts a flow rate of the dilution gas introduced into the dilutor, 
 a filter passing flow rate adjusting device that adjusts a flow rate of the diluted exhaust gas passing the collection filter, 
 a control part that keeps a sum of the flow rate of the diluted exhaust gas introduced into the mass-related value measurement device and the flow rate of the diluted exhaust gas passing the collection filter at a constant value by controlling the filter passing flow rate adjusting device based on the flow rate of the diluted exhaust gas introduced into the mass-related value measurement device, and 
 an information processing part that calculates a correlation between a mass measurement value of the particulate matters collected by the collection filter during a predetermined period while the engine is in operation and a time integrated value of the mass-related value measurement data during the predetermined period as being a time series change data of the mass-related value measured by the mass-related, value measurement device and that converts the mass-related value measurement data to the time series change data of the mass of the particulate matters based on the correlation.